1. Field of The Invention
The present invention relates to the field of exercise equipment, in general, and to an improved stationary exercise bicycle, in particular.
2. Prior Art
Relatively recent trends towards physical fitness awareness have led to an increase in the number of individuals exercising on a regular basis in order to keep physically fit. Several types of exercise equipment are currently in use to provide exercise to persons who wish to keep physically fit without venturing outdoors. One of the most popular of such indoor exercise devices is the stationary exercise bicycle.
A number of present day gymnasiums and exercise clubs have some type of stationary exercise bicycle apparatus whereby a person pedals a simulated bicycle as a form of exercise. Early exercise bicycles included apparatus designed to support a conventional bicycle so that the rear wheel thereof can rotate against a frictional load. These types of devices fall into several general categories, the first of which connects the front axle and the bottom bracket of the bicycle to a frame in order to support the bicycle. The rear wheel drives against a roller, which in turn is connected to a loading mechanism. Typically, the rear wheel drives a flywheel and a variable resistance load. A second type of apparatus used with a conventional bicycle supports the rear wheel, either on a pair of rollers or by a fixed support at the rear axle. Each of the above devices has numerous drawbacks for use as an exercise device.
The devices using a bottom bracket support allow the use of a real bicycle frame but fail to provide a realistic resistance and ride simulation. This type of equipment usually has one roller contacting the rear wheel. The devices using one or more rollers to support the rear wheel have stability and slippage problems. If the roller is behind the rear axle, the roller must be relatively long because the wheel wobbles and moves sideways and frequently falls off the roller. Conversely, if the roller is in front of the axle, the wheel stays centered but does not maintain adequate contact during periods of maximum torque on the rear wheel. In both cases, if a realistic resistance is applied, the rear tire slips on the roller.
For example, during maximum performance periods, the bicycle rider is not on the saddle, but is leaning over the handlebar and, essentially, standing on the pedals. As the weight of the rider shifts forward, the force on the rear wheel decreases and the weight on the front wheel increases, causing slippage of the rear wheel. Further, in this position with a bicycle on the bottom bracket support, the bicycle frequently pivots about the bottom bracket, effectively removing the rear wheel from contact with the supporting roller or rollers. Thus, just when the maximum resistance is needed to prevent slippage at the rear wheel, the rear wheel is at minimum friction contact with the resistance rollers and, therefore, slips.
More sophisticated bicycle simulating equipment has been developed through the years leading to current stationary bicycle designs which sometimes do not resemble standard bicycles at all. These devices consist primarily of bicycle cranks driven by the feet of the exerciser and are drivingly coupled, usually by a chain drive, to a flywheel to provide resistance to the pedal motion thereby providing the exerciser with a force to work against. Both the appearance and the functional features of the exercise bicycle are continuously undergoing change and improvement. However, they still suffer from several drawbacks
The drawbacks associated with more sophisticated stationary bicycle devices include relatively complex load providing components thus inherently increasing the overall production cost of the bicycle and the need for maintenance and repair. Also, most prior art stationary bicycles use weighted flywheels that eventually create a balancing problem preventing the user from obtaining a smooth ride potentially leading to injury by micro-trauma to various body structures.
Also, most prior art stationary bicycles allow for size and configuration adjustment only by incremental units which are in the range of 1xe2x80x2. Consequently, optimal customization to an individual""s characteristics is virtually impossible thus, again, potentially leading to injury to various body structures such as joints and ligaments. In addition, the adjustment providing mechanisms of most prior art stationary bicycles are either mechanically complex or unreliable thereby leading to high production cost, susceptibility to break down, or both.
Still further, most prior art stationary bicycles include frames made of standard forged steel which are assembled by a welding process. Typically, the frame is painted with a powder coat baked at approximately 400 degrees. This type of frame and associated paint covering may potentially lead to frame warping and reduced longevity because of rust or other deteriorating process.
Most prior art stationary bicycle devices have tried to provide a realistic simulation of a smooth ride and load resistance experience when riding a bicycle.
However, the previous attempts to accurately replicate or simulate these various load effects have all had their drawbacks. Typical load variables can include wind resistance, whether the rider is going up hill or down hill, the inertia of the rider and bicycle, the friction inherent in the bicycle itself and the frictional resistance between the bicycle tires and riding surface. Proper simulation of realistic load resistance involved providing the intended ride with the ability to fine-tune by relatively small increments the load applied to the pedals of the stationary bicycle.
For example, the effective wind resistance has been simulated by rotating fan blades, which are mechanically coupled to the rotational speed of the bicycle wheel. While the rotating fan blades can provide a force that increase as the square of the rotational speed of the fan blades, these fans are noisy, inaccurate, not readily adjustable and cannot be adjusted to account for variation in wind resistance that will occur with riders of different size and weight.
Similar prior devices have attempted to simulate the amount of load to be applied by either a mechanical or electronic brake system. A typical mechanical brake involves a friction belt that wraps around a moving surface to cause a frictional drag on that rotating surface depending upon the tension of the belt. Typically, the friction belt is positioned within a grooved formed on the peripheral surface of a flywheel. These mechanical systems, however, cannot be accurately calibrated, have a slow response time and are subject to load variations over time as the elements of the mechanical system go out of adjustment and alignment. Further, the frictional load varies with the environmental temperature and with the temperature of the frictionally engaging parts.
The prior art mechanical systems, thus, have poor repeatability, high variation in drag and are difficult or impossible to accurately calibrate to a given load. Further, a large force is typically required to be exerted on the friction belt in order to adequately vary the frictional loads. Still further, prior art mechanical systems are not provided with emergency braking functions allowing a given rider to quickly immobilize the flywheel or other mechanisms linked to the pedal in the event that an emergency situation arises.
Electronic prior art braking systems have some advantages over the mechanical systems, but the accuracy of the simulated ride depends upon several factors, including how accurately the system can be calibrated and the realism of the program with which the electronic brake is varied. Furthermore, these systems are typically much more complex than mechanical systems and, hence, considerably more expensive. Furthermore, they often require costly maintenance and repair. Accordingly, there exists a need for an improved stationary bicycle.
The invention is directed to a stationary bicycle which has load-providing components allowing for fine-tuned adjustment of the selected load. The load providing components are made of relatively simple mechanical components so as to increase the reliability, reduce the maintenance and provide a relatively smooth cycling feel.
In addition, the stationary bicycle is manufactured using specific materials and processes so as to provide for a reliable product having a relatively long life cycle characterized by reliable functioning.
Furthermore, the stationary bicycle described herein comprises a design which allows for ergonomic fine tuning of the relative positioning between the various components thereof so as to provide ergonomic adjustments which can reduce the risk of injury to the body of the individual using the device and, thereby, allowing for a more efficient workout.